Optical system with semiautomatic diaphragm adjustment to preselected position



p T952 K. H. SCHUTZ OPTICAL SYSTEM WITH SEMIAUTOMATIC DIAPHRAGMADJUSTMENT TO PRESELECTED POSITION Filed May 51, 1950 AGENT PatentedSept. 30, 1952 TED I j :-.2,612,o'9si '7 .nrTroAL tsYsrrEM- w1H--=si1M-IAU'r-;o- ".MATI'C i DIAPHRAGM ADJUSTMENT "r sens SELECTED-PosrrmN Germany i 3 Application May'31, 1950;ISerial'SNo. 1651193 InGermany N0veni'ber"1'li," 1949 13 Claims. (01:95am

. fl he pre'sent invention relates toran optical vsystem for cameras,particularly but not exclusively for reflex cameras 'in which the imageobjective "also serves as the-finder objective, and

has for 'its -primary :object .the provision, in a camera, ofuneansiorsemi-automatically returning the diaphragm ther'eof to a;preselectedposition after it hasbeendisplaced therefrom bythe operator.

.-In .azreflex'camera-of the above-described class itis usuallynecessary to use. different diaphragm openings. for the. .findingprocess and for i the actual shot;' or taking of the picture; 'thusitwill be desirable to adjust .the diaphragm'opening to its :maximumwhenethe objective is employed for centeringpurposes: in order to.obtain-abright reflected ipicture; while in many cases *over-exposurewould resultunless the opening were returned to its. predeterminedsize'beforesreleasing the shutter. It is an inherent disadvantage ofthese cameras 'thattheuser is apt to forget this re-adjustment of thediaphragm and, thereby, to spoil the picture sought to be taken.

It is, accordingly, another object of this invention to provide'meansfor coupling the return of With these objects in view the inventionprovides, essentially, first indexing means for arresting the diaphragmin any one of a plurality of preselectable positions, second indexingmeans for locking the diaphragm in its position of maximum opening, atrip member (perferably controlled by the shutter release of the camera)operable in the position of maximum opening of the diaphragm to disablethe second indexing means and render the first indexing means effective,and resilient means returning the diaphragm to its preselected positionunder control of the first indexing means following the operation of thetrip member.

The invention will be described with reference to the accompanyingdrawing in which:

Fig. 1 is an axial section through the diaphragm adjusting mechanism ofa camera according to the invention; and

1 "Illhei diaphragm I is mounted in its cylindrical hous'ingfl n-relative to which :the diaphragm ring ll is rotatable by means of 'a-pin IZ Z-paSS1ng through a fs'lot' in' the:housing. :The housing lt is'thradedly secured to the stationary cylinder '6. "The diaphragm controlelement 2 comprises an outer- 'sleeve 2a having afi forked appendage 2"which straddles the-pin l2, an inner sleevezb rotatable inunison withouter sleeve 2a by means of 'a connecting pinl 3sengaged'byi'the mm 2',and a'm'illed'flange 2c fixed to'the outer sleevei2a. l An annularrecess 14 on the' inner sleeve zbsand a c'o-operatingshouldei' l 5- on-the outer sleeve in allow lir'nited :axial- -displacement 10f vthe:outer sleeve with respect to lthe inner'sleeve 2b, the

- pin l3 acting as ia stop forthe forward .movement of sleeve 2a.

A retaining ring I 6,:threadedlyengaging .the housing In,-hol'cls---'thediaphragmring II and the inner sleeve 2'b in place. JAn.annularmem- 1 her :l-'|," forming -a detached'forward continuation or:the sleeve 2b,: is rotatably positioned between the latter: andanrannuilar zshoulder l8 projecting from housing 1 0. A pin- .9;projecting .from

"the 'annul'ar rmember ll, listengageable .by the 'ends oi fork l2.whenfthe :outer sleeveg2a is in its I normal position;:asrillustrated,thereby coupling the.- member. lT with' the control member 2a, 2b andwithithe diaphragm ring I l. for simultaneous rotation. .sleeve". 2b: isaxially spaced 1 from mem- "her I1 ovenpa'rtzof. its periphery(right-hand portion1of-' Fi'g..1)':toJproVidexcIearance for the pin 12.

v I Amesilient indexrfinger -3;. secured T'GO the annu'lar member. I1;;istadapted tov vfall into notches provided in'tithe annularshoulder.l8, thereby at 2| is adapted to fall into a notch 22, provided on theinner periphery of flange 2c, when this flange has been rotated into aposition corresponding to the maximum opening of diaphragm I. Finger 5may be disengaged from notch 22 by means of a trip button 1, slidablyheld in a nipple 8 adapted to have the shutter release (not shown) ofthe camera connected thereto.

The operation of the arrangement described is as follows:

By manually rotating the flange 20, upon removal of finger 3 from itsnotch in shoulder l8 by suitable means (not shown), the user displacesthe diaphragm ring H and with it the annular member I! relative-to thehousing Muntil the index finger 3 falls into a desired notch. in theannular shoulder l8. Next, for the purpose of viewing the finder image,the user retracts the outer sleeve 2a by axially displacing the fiange20, thereby disengaging the fork ZJfrOmFthe-pin 9, and continuesrotation of the diaphragm, con-f. trol element 211, 212 until the fingersnaps into notch 22. This tensions the spring ill-:which, however, issufficiently yieldable to prevent disengagement cf the finger 3 from theselected notch. After the user has satisfied himself of the correctcentering of the objective, he releases the shutter, thus actuating pushbutton 1 and tripping the finger 5 out of engagement with notch 22.Spring 4 is thereby enabled to return the elements 2, 2a, 2b, 20, l land I2 into a position in which the pin 9 re-engages fork 2, by cammingaside the first prong thereof and being stopped by the second which forthis purpose may be suitably lengthened. It will thus be seen that thediaphragm ring II will now re-occupy the'position in which it founditself when the-@index 1. In a camera, in combination, a stationary.

housing, a control element, anactuating member and a stop member'allconcentrically mounted on said housing for rotation about a common axis,a diaphragm having an opening variable by rotation of said controlelement relative to said housing, spring means urging rotation of saidcontrol element in a first sense tending-bodecrease the size of saidopening, said actuating member being permanently coupled. with saidcontrol element and being axially displaceable between a first and asecond axial position with respect to said housing, a first formation onsaid stop member, first abutment means permanently entrained by saidactuating member and engageable by said first formation upon rotation ofsaid actuating member in 'said first sense,

thereby preventing rotation of said actuating member and of said controlelement beyond a predetermined position relative to said stop memberupon displacement of the actuating member toward closure of thediaphragm, a second formation on said stop member, second abutment meanson said actuatingmember' engageable by said second formation uponrotation of said actuating member in a second sense, opposite said firstsense, in said second axial position only but permanently disengagedfrom said second formation in said first axial position of saidactuating member, said actuating member thus rotatively cntraining saidstop member when rotated in said second axial position toward maximumopening of the diaphragm, first indexing means adapted to hold said stopmember in an angular position selected by thus rotating said actuatingmember, second indexing means adapted to hold said control element in anextreme position, corresponding to maximum diaphragm opening, uponrotation of said actuating member in said second sense, and releasemeans for inactivating said second indexing means, thereby enabling saidspring means to remove said actuating member and said control elementfromsaid extreme position to another position corresponding to apreselected setting of said stop member.

2. The combination according to claim 1 wherein said actuating member isprovided with an axially directed bifurcation, said second abutmentmeans comprising one of the prongs of said bifurcation, at least saidsecond formation being part of a pin projecting from said stop memberand engageble by said prongs.

3. The combination according to claim 2, wherein said control element isprovided with a projection permanently received between the prongs ofsaid bifurcation, thereby coupling said control element with saidactuating member.

KARL HELNZ scHiiTZ.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,222,298 Nerwin Nov. 19, 19402,262,509 McNabb Nov. 11, 1941 2,269,401 Steiner Jan. 6, 1942 2,311,822Frankel Feb. 23, 1943 FOREIGN PATENTS Number Country Date 409,777 GreatBritain May 10, 1934

